[Autofill Assistant] Ui framework should only consume space when used.

Bug: b/152013302
Change-Id: I3bfc9628c01c130e49630bfddf08898ce9b68838
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2111319
Auto-Submit: Clemens Arbesser <arbesser@google.com>
Commit-Queue: Sandro Maggi <sandromaggi@google.com>
Reviewed-by: Sandro Maggi <sandromaggi@google.com>
Cr-Commit-Position: refs/heads/master@{#752398}

chrome/android/features/autofill_assistant/java/src/org/chromium/chrome/browser/autofill_assistant/generic_ui/AssistantGenericUiViewBinder.java

@@ -4,6 +4,7 @@
 
 package org.chromium.chrome.browser.autofill_assistant.generic_ui;
 
+import android.view.View;
 import android.view.ViewGroup;
 
 import org.chromium.ui.modelutil.PropertyKey;
@@ -31,6 +32,9 @@ class AssistantGenericUiViewBinder
             view.mViewContainer.removeAllViews();
             if (model.get(AssistantGenericUiModel.VIEW) != null) {
                 view.mViewContainer.addView(model.get(AssistantGenericUiModel.VIEW));
+                view.mViewContainer.setVisibility(View.VISIBLE);
+            } else {
+                view.mViewContainer.setVisibility(View.GONE);
             }
         } else {
             assert false : "Unhandled property detected in AssistantGenericUiViewBinder!";